Irbesartan - Warnings and Precautions

5 WARNINGS AND PRECAUTIONS Hypotension: Correct volume depletion prior to administration.

Impaired renal function.

Thiazide diuretics may cause an exacerbation or activation of systemic lupus erythematosus.

Acute angle-closure glaucoma, acute myopia, and choroidal effusion.

5.1 Fetal Toxicity Irbesartan and hydrochlorothiazide tablets can cause fetal harm when administered to a pregnant woman.

Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity and death.

Resulting oligohydramnios can be associated with fetal lung hypoplasia and skeletal deformations.

Potential neonatal adverse effects include skull hypoplasia, anuria, hypotension, renal failure, and death.

When pregnancy is detected, discontinue irbesartan and hydrochlorothiazide tablets as soon as possible [see Use in Specific Populations ].

Thiazides cross the placenta and use of thiazides during pregnancy is associated with a risk of fetal or neonatal jaundice, thrombocytopenia, and possibly other adverse reactions that have occurred in adults.

5.2 Hypotension in Volume or Salt-Depleted Patients Excessive reduction of blood pressure was rarely seen in patients with uncomplicated hypertension treated with irbesartan alone (<0.1%) or with irbesartan and hydrochlorothiazide (approximately 1%).

Initiation of antihypertensive therapy may cause symptomatic hypotension in patients with intravascular volume or sodium depletion, e.g., in patients treated vigorously with diuretics or in patients on dialysis.

Such volume depletion should be corrected prior to administration of antihypertensive therapy.

If hypotension occurs, the patient should be placed in the supine position and, if necessary, given an intravenous infusion of normal saline.

A transient hypotensive response is not a contraindication to further treatment, which usually can be continued without difficulty once the blood pressure has stabilized.

5.3 Hypersensitivity Reaction Hydrochlorothiazide Hypersensitivity reactions to hydrochlorothiazide may occur in patients with or without a history of allergy or bronchial asthma, but are more likely in patients with such a history.

5.4 Systemic Lupus Erythematosus Hydrochlorothiazide Thiazide diuretics have been reported to cause exacerbation or activation of systemic lupus erythematosus.

5.5 Electrolyte and Metabolic Imbalances Irbesartan and Hydrochlorothiazide In double-blind clinical trials of various doses of irbesartan and hydrochlorothiazide, the incidence of hypertensive patients who developed hypokalemia (serum potassium <3.5 mEq/L) was 7.5% versus 6.0% for placebo; the incidence of hyperkalemia (serum potassium >5.7 mEq/L) was <1.0% versus 1.7% for placebo.

No patient discontinued due to increases or decreases in serum potassium.

On average, the combination of irbesartan and hydrochlorothiazide had no effect on serum potassium.

Higher doses of irbesartan ameliorated the hypokalemic response to hydrochlorothiazide.

Coadministration of irbesartan and hydrochlorothiazide tablets with potassium-sparing diuretics, potassium supplements, potassium-containing salt substitutes or other drugs that raise serum potassium levels may result in hyperkalemia, sometimes severe.

Monitor serum potassium in such patients.

Hydrochlorothiazide Hydrochlorothiazide can cause hypokalemia and hyponatremia.

Hypomagnesemia can result in hypokalemia which appears difficult to treat despite potassium repletion.